Upgrade to Rails 5

In this summer I want to work on upgrading the code of plots2 repository to rails 5.0 and rails 5.1. The project would have many challenges to conquer like converting the code of website compatible to rails 4.2 , writing tests for the whole website, finding gems compatible to rails 5.0 and then converting the code into rails 5.0 and then similarly to rails 5.1 and rails 5.2.